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Behcet's disease (BD) is an immune-mediated vasculitis related to imbalances between the innate and adaptive immune response. Infectious agents or environmental factors may trigger the disease in genetically predisposed individuals. HLA-B51 is the genetic factor stronger associated with the disease, although the bases of this association remain elusive. NK cells have also been implicated in the etiopathogenesis of BD. A family of NK receptors, Killer-cell Immunoglobulin-like Receptor (KIR), with a very complex organization, is very important in the education and control of the NK cells by the union to their ligands, most of them, HLA class I molecules. This study aimed to investigate the contribution of certain KIR functional polymorphisms to the susceptibility to BD. A total of 466 BD patients and 444 healthy individuals were genotyped in HLA class I (A, B, and C). The set of KIR genes and the functional variants of KIR3DL1/DS1 and KIR2DS4 were also determined. Frequency of KIR3DL1*004 was lower in patients than in controls (0.15 vs. 0.20, P = 0.005, Pc = 0.015; OR = 0.70; 95% CI 0.54-0.90) in both B51 positive and negative individuals. KIR3DL1*004, which encodes a misfolded protein, is included in a common telomeric haplotype with only one functional KIR gene, KIR3DL2. Both, KIR3DL1 and KIR3DL2 sense pathogen-associated molecular patterns but they have different capacities to eliminate them. The education of the NK cells depending on the HLA, the balance of KIR3DL1/KIR3DL2 licensed NK cells and the different capacities of these receptors to eliminate pathogens could be involved in the etiopathogenesis of BD., This work was supported by Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III (ISCIII, 13/01118 and 16/01373), Fondos FEDER and Plan Andaluz de Investigacion (CTS-0197).

How genetic variations mediate normal and abnormal biological function is a major issue in biology and medicine. The enormous number of genomic sequences, and their frequent and rare variations identified in humans, require efficient approaches aimed at dissecting functional correlates. In this review we will focus on the importance of the assessment of well-defined intermediate phenotypes, on the set up of transcriptomic approaches in diseased cells and on the modulation of expression by sequence variations modulating mRNA splicing or influencing protein multimerization. These information provide the molecular bases of associations discovered through genomic approaches, and might open new avenues toward the design of novel and specific diagnostic, prophylactic or therapeutic interventions. Taking into account our previous and current experimental activities we shall focus on a few examples and open issues in cardiovascular disorders, the main clinical topic of this short review.

The role of the human beta-defensin 1 (hBD-1) in the susceptibility to the onset of the Atypical Squamous Cells of Undetermined Significance (ASCUS) lesion, in the presence or not of HPV infection, is still unknown. In the current study, the three functional single nucleotide polymorphisms (SNPs) -52G A, -44C G, and -20G A at the 5' un-translated region (UTR) of DEFB1 gene, encoding hBD-1, were analyzed in ASCUS lesion gynecological patients and healthy women from the north-east of Italy (Trieste). Cervical samples from 249 European-Caucasian women were collected, screened for HPV and cytologically evaluated; DEFB1 genotyping has been performed by direct sequencing. No significant differences were found for -52G A, -44C G, and -20G A SNPs allele and genotype frequencies between women with and without ASCUS lesions. DEFB1 minor haplotypes were significantly more frequent in ASCUS lesion positive than negative women, associating with an increased risk of this type of lesion. When women were stratified according to HPV infection status, significant differences in the distribution of -52G A SNP genotype frequencies were found: the presence of the A allele in the homozygous genotype A/A associated with a lower risk of developing ASCUS lesions in HPV negative women. DEFB1 minor haplotypes were also associated with an increased risk of developing ASCUS lesions, being significantly more frequent in HPV negative women with lesions, than without lesions. Although these results highlight the possible involvement of DEFB1, further studies are needed to support the role of DEFB1 in the modulation of the susceptibility to ASCUS lesions.

We investigated the association between MBL2 gene exon 1 functional polymorphisms and autoimmune thyroid disease (AITD) in 163 Brazilian patients (87 with Hashimoto thyroiditis, HT; 76 with Graves' disease) and 214 healthy controls. Individuals carrying MBL2 O allele are at higher risk of developing AITD (OR = 1.58, 95\% CI: 1.11-2.26; P-value = 0.009) and HT (OR = 1.67, 95\% CI: 1.09-2.55; P-value = 0.013) as suggesting a possible role for mannose-binding lectin in influencing disease susceptibility.

Background Linkage and congenic strain analyses using the nonobese diabetic (NOD) mouse as a model for human type 1 autoimmune diabetes (T1D) have identified several NOD mouse Idd (insulin dependent diabetes) loci, including Slc11a1 (formerly known as Nramp1). Genetic variants in the orthologous region encompassing SLC11A1 in human chromosome 2q35 have been reported to be associated with various immune-related diseases including T1D. Here, we have conducted association analysis of this candidate gene region, and then investigated potential correlations between the most T1D-associated variant and RNA expression of the SLC11A1 gene and its splice isoform. Methods Nine SNPs (rs2276631, rs2279015, rs1809231, rs1059823, rs17235409 (D543N), rs17235416 (3'UTR), rs3731865 (INT4), rs7573065 (-237 C→T) and rs4674297) were genotyped using TaqMan genotyping assays and the polymorphic promoter microsatellite (GT)n was genotyped using PCR and fragment length analysis. A maximum of 8,863 T1D British cases and 10,841 British controls, all of white European descent, were used to test association using logistic regression. A maximum of 5,696 T1D families were also tested for association using the transmission/disequilibrium test (TDT). We considered P ≤ 0.005 as evidence of association given that we tested nine variants in total. Upon identification of the most T1D-associated variant, we investigated the correlation between its genotype and SLC11A1 expression overall or with splice isoform ratio using 42 PAXgene whole blood samples from healthy donors by quantitative PCR (qPCR). Results Using the case-control collection, rs3731865 (INT4) was identified to be the variant most associated with T1D (P = 1.55 × 10-6). There was also some evidence of association at rs4674297 (P = 1.57 × 10-4). No evidence of disease association was obtained at any of the loci using the family collections (PTDT ≥ 0.13). We also did not observe a correlation between rs3731865 genotypes and SLC11A1 expression overall or with splice isoform expression. Conclusion We conclude that rs3731685 (INT4) in the SLC11A1 gene may be associated with T1D susceptibility in the European ancestry population studied. We did not observe a difference in SLC11A1 expression at the RNA level based on the genotypes of rs3731865 in whole blood samples. However, a potential correlation cannot be ruled out in purified cell subsets especially monocytes or macrophages.

Contains fulltext : 80760.pdf (Publisher’s version ) (Closed access) Ficolins are pattern-recognition molecules that appear to be relevant for innate immune defence against infections. The ficolin genes in Caucasians are polymorphic and genetic variations may have functional consequences, both in relation to function and concentration. Low levels of Ficolin-2 have been suggested to associate with recurrent respiratory tract infections (RTI), whereas data on Ficolin-3 are still very limited. We investigated the association between variation in genes encoding Ficolin-2 (FCN2) and Ficolin-3 (FCN3) and frequency of RTI during the first 4 years of life. The study population consisted of 900 children from a large, population-based birth cohort of Dutch children, followed prospectively from birth to 4 years of age. The number of RTI was assessed by annual parental questionnaires. Nine single nucleotide polymorphisms in FCN2 and two in FCN3, all based on functionality or haplotype-tagging characteristics, were determined and haplotypes constructed. We found that single nucleotide polymorphisms in FCN2 and FCN3 were not associated with increased risk of RTI during the first 4 years of life. No difference existed between haplotype-frequencies of FCN2 and FCN3 in children grouped according to the reported number of RTI. In conclusion, at a population level, genetic variation in ficolin genes FCN2 and FCN3 do not seem to contribute to the risk of RTI in Caucasian children.

Objective—Functional polymorphisms contributing to coagulation factor levels are preferential markers for association studies aimed at identifying prothrombic genetic components.Methods and Results—Factor V (FV) microsatellite genotypes were found to be associated with FV levels (P=0.003). Single nucleotide polymorphisms analysis and sequencing of the promoter and of coding regions identified two polymorphisms (Met2120Thr, Asp2194Gly) present in 20% of the population (n=1013) that are responsible for genotype-phenotype associations. The effect of the Met2120Thr polymorphism, both in plasma (mean reduction of FV level in the heterozygous condition: 25%) and in recombinant FV studies (34% reduction), was comparable to that of the Asp2194Gly change (20% and 34%, respectively). The study of 10 subjects with a rare genotype indicated that the Asp2194Gly substitution is the functional determinant of the reduced FV levels associated with the FVHR2 haplotype. Among Leiden carriers, the doubly heterozygous condition for FV2120Thr was found to be associated with a significantly increased activated protein-C resistance (APCR) (PP=0.009) in symptomatic than in asymptomatic subjects.Conclusions—Extensive analysis of FV polymorphisms indicated that changes in the C2 domain modulate FV levels and might increase APCR and thrombotic risk in FV Leiden carriers through a pseudohomozygous mechanism.

The control of coagulation factor levels has a pivotal role in thrombophilia and known functional polymorphisms explain only a minor part of the coagulation factor level variance. Several studies provide evidence for i) interaction of polymorphisms and their combination with environmental factors; ii) molecular mechanisms mediating activation of coagulation proteins by environmental factors; iii) molecular mechanisms mediating transcriptional control of thrombophilia genes by environmental factors. However, the vast majority of molecular regulation by environmental factors is still unknown. Understanding of gene-gene and gene-environment interactions will require a detailed knowledge of regulatory regions of thrombophilia genes and of regulatory proteins.